var Markdown;

if (typeof exports === "object" && typeof require === "function") // we're in a CommonJS (e.g. Node.js) module
  Markdown = exports;
else
  Markdown = {};

// The following text is included for historical reasons, but should
// be taken with a pinch of salt; it's not all true anymore.

//
// Wherever possible, Showdown is a straight, line-by-line port
// of the Perl version of Markdown.
//
// This is not a normal parser design; it's basically just a
// series of string substitutions.  It's hard to read and
// maintain this way,  but keeping Showdown close to the original
// design makes it easier to port new features.
//
// More importantly, Showdown behaves like markdown.pl in most
// edge cases.  So web applications can do client-side preview
// in Javascript, and then build identical HTML on the server.
//
// This port needs the new RegExp functionality of ECMA 262,
// 3rd Edition (i.e. Javascript 1.5).  Most modern web browsers
// should do fine.  Even with the new regular expression features,
// We do a lot of work to emulate Perl's regex functionality.
// The tricky changes in this file mostly have the "attacklab:"
// label.  Major or self-explanatory changes don't.
//
// Smart diff tools like Araxis Merge will be able to match up
// this file with markdown.pl in a useful way.  A little tweaking
// helps: in a copy of markdown.pl, replace "#" with "//" and
// replace "$text" with "text".  Be sure to ignore whitespace
// and line endings.
//


//
// Usage:
//
//   var text = "Markdown *rocks*.";
//
//   var converter = new Markdown.Converter();
//   var html = converter.makeHtml(text);
//
//   alert(html);
//
// Note: move the sample code to the bottom of this
// file before uncommenting it.
//

(function () {

  function identity(x) { return x; }
  function returnFalse(x) { return false; }

  function HookCollection() { }

  HookCollection.prototype = {

    chain: function (hookname, func) {
      var original = this[hookname];
      if (!original)
        throw new Error("unknown hook " + hookname);

      if (original === identity)
        this[hookname] = func;
      else
        this[hookname] = function (x) { return func(original(x)); }
    },
    set: function (hookname, func) {
      if (!this[hookname])
        throw new Error("unknown hook " + hookname);
      this[hookname] = func;
    },
    addNoop: function (hookname) {
      this[hookname] = identity;
    },
    addFalse: function (hookname) {
      this[hookname] = returnFalse;
    }
  };

  Markdown.HookCollection = HookCollection;

  // g_urls and g_titles allow arbitrary user-entered strings as keys. This
  // caused an exception (and hence stopped the rendering) when the user entered
  // e.g. [push] or [__proto__]. Adding a prefix to the actual key prevents this
  // (since no builtin property starts with "s_"). See
  // http://meta.stackoverflow.com/questions/64655/strange-wmd-bug
  // (granted, switching from Array() to Object() alone would have left only __proto__
  // to be a problem)
  function SaveHash() { }
  SaveHash.prototype = {
    set: function (key, value) {
      this["s_" + key] = value;
    },
    get: function (key) {
      return this["s_" + key];
    }
  };

  Markdown.Converter = function () {
    var pluginHooks = this.hooks = new HookCollection();
    pluginHooks.addNoop("plainLinkText");  // given a URL that was encountered by itself (without markup), should return the link text that's to be given to this link
    pluginHooks.addNoop("preConversion");  // called with the orignal text as given to makeHtml. The result of this plugin hook is the actual markdown source that will be cooked
    pluginHooks.addNoop("postConversion"); // called with the final cooked HTML code. The result of this plugin hook is the actual output of makeHtml

    //
    // Private state of the converter instance:
    //

    // Global hashes, used by various utility routines
    var g_urls;
    var g_titles;
    var g_html_blocks;

    // Used to track when we're inside an ordered or unordered list
    // (see _ProcessListItems() for details):
    var g_list_level;

    this.makeHtml = function (text) {

      //
      // Main function. The order in which other subs are called here is
      // essential. Link and image substitutions need to happen before
      // _EscapeSpecialCharsWithinTagAttributes(), so that any *'s or _'s in the <a>
      // and <img> tags get encoded.
      //

      // This will only happen if makeHtml on the same converter instance is called from a plugin hook.
      // Don't do that.
      if (g_urls)
        throw new Error("Recursive call to converter.makeHtml");

      // Create the private state objects.
      g_urls = new SaveHash();
      g_titles = new SaveHash();
      g_html_blocks = [];
      g_list_level = 0;

      text = pluginHooks.preConversion(text);

      // attacklab: Replace ~ with ~T
      // This lets us use tilde as an escape char to avoid md5 hashes
      // The choice of character is arbitray; anything that isn't
      // magic in Markdown will work.
      text = text.replace(/~/g, "~T");

      // attacklab: Replace $ with ~D
      // RegExp interprets $ as a special character
      // when it's in a replacement string
      text = text.replace(/\$/g, "~D");

      // Standardize line endings
      text = text.replace(/\r\n/g, "\n"); // DOS to Unix
      text = text.replace(/\r/g, "\n"); // Mac to Unix

      // Make sure text begins and ends with a couple of newlines:
      text = "\n\n" + text + "\n\n";

      // Convert all tabs to spaces.
      text = _Detab(text);

      // Strip any lines consisting only of spaces and tabs.
      // This makes subsequent regexen easier to write, because we can
      // match consecutive blank lines with /\n+/ instead of something
      // contorted like /[ \t]*\n+/ .
      text = text.replace(/^[ \t]+$/mg, "");

      // Turn block-level HTML blocks into hash entries
      text = _HashHTMLBlocks(text);

      // Strip link definitions, store in hashes.
      text = _StripLinkDefinitions(text);

      text = _RunBlockGamut(text);

      text = _UnescapeSpecialChars(text);

      // attacklab: Restore dollar signs
      text = text.replace(/~D/g, "$$");

      // attacklab: Restore tildes
      text = text.replace(/~T/g, "~");

      text = pluginHooks.postConversion(text);

      g_html_blocks = g_titles = g_urls = null;

      return text;
    };

    function _StripLinkDefinitions(text) {
      //
      // Strips link definitions from text, stores the URLs and titles in
      // hash references.
      //

      // Link defs are in the form: ^[id]: url "optional title"

      /*
       text = text.replace(/
       ^[ ]{0,3}\[(.+)\]:  // id = $1  attacklab: g_tab_width - 1
       [ \t]*
       \n?                 // maybe *one* newline
       [ \t]*
       <?(\S+?)>?          // url = $2
       (?=\s|$)            // lookahead for whitespace instead of the lookbehind removed below
       [ \t]*
       \n?                 // maybe one newline
       [ \t]*
       (                   // (potential) title = $3
       (\n*)           // any lines skipped = $4 attacklab: lookbehind removed
       [ \t]+
       ["(]
       (.+?)           // title = $5
       [")]
       [ \t]*
       )?                  // title is optional
       (?:\n+|$)
       /gm, function(){...});
       */

      text = text.replace(/^[ ]{0,3}\[(.+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?(?=\s|$)[ \t]*\n?[ \t]*((\n*)["(](.+?)[")][ \t]*)?(?:\n+)/gm,
          function (wholeMatch, m1, m2, m3, m4, m5) {
            m1 = m1.toLowerCase();
            g_urls.set(m1, _EncodeAmpsAndAngles(m2));  // Link IDs are case-insensitive
            if (m4) {
              // Oops, found blank lines, so it's not a title.
              // Put back the parenthetical statement we stole.
              return m3;
            } else if (m5) {
              g_titles.set(m1, m5.replace(/"/g, "&quot;"));
            }

            // Completely remove the definition from the text
            return "";
          }
      );

      return text;
    }

    function _HashHTMLBlocks(text) {

      // Hashify HTML blocks:
      // We only want to do this for block-level HTML tags, such as headers,
      // lists, and tables. That's because we still want to wrap <p>s around
      // "paragraphs" that are wrapped in non-block-level tags, such as anchors,
      // phrase emphasis, and spans. The list of tags we're looking for is
      // hard-coded:
      var block_tags_a = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del"
      var block_tags_b = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math"

      // First, look for nested blocks, e.g.:
      //   <div>
      //     <div>
      //     tags for inner block must be indented.
      //     </div>
      //   </div>
      //
      // The outermost tags must start at the left margin for this to match, and
      // the inner nested divs must be indented.
      // We need to do this before the next, more liberal match, because the next
      // match will start at the first `<div>` and stop at the first `</div>`.

      // attacklab: This regex can be expensive when it fails.

      /*
       text = text.replace(/
       (                       // save in $1
       ^                   // start of line  (with /m)
       <($block_tags_a)    // start tag = $2
       \b                  // word break
       // attacklab: hack around khtml/pcre bug...
       [^\r]*?\n           // any number of lines, minimally matching
       </\2>               // the matching end tag
       [ \t]*              // trailing spaces/tabs
       (?=\n+)             // followed by a newline
       )                       // attacklab: there are sentinel newlines at end of document
       /gm,function(){...}};
       */
      text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del)\b[^\r]*?\n<\/\2>[ \t]*(?=\n+))/gm, hashElement);

      //
      // Now match more liberally, simply from `\n<tag>` to `</tag>\n`
      //

      /*
       text = text.replace(/
       (                       // save in $1
       ^                   // start of line  (with /m)
       <($block_tags_b)    // start tag = $2
       \b                  // word break
       // attacklab: hack around khtml/pcre bug...
       [^\r]*?             // any number of lines, minimally matching
       .*</\2>             // the matching end tag
       [ \t]*              // trailing spaces/tabs
       (?=\n+)             // followed by a newline
       )                       // attacklab: there are sentinel newlines at end of document
       /gm,function(){...}};
       */
      text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math)\b[^\r]*?.*<\/\2>[ \t]*(?=\n+)\n)/gm, hashElement);

      // Special case just for <hr />. It was easier to make a special case than
      // to make the other regex more complicated.

      /*
       text = text.replace(/
       \n                  // Starting after a blank line
       [ ]{0,3}
       (                   // save in $1
       (<(hr)          // start tag = $2
       \b          // word break
       ([^<>])*?
       \/?>)           // the matching end tag
       [ \t]*
       (?=\n{2,})      // followed by a blank line
       )
       /g,hashElement);
       */
      text = text.replace(/\n[ ]{0,3}((<(hr)\b([^<>])*?\/?>)[ \t]*(?=\n{2,}))/g, hashElement);

      // Special case for standalone HTML comments:

      /*
       text = text.replace(/
       \n\n                                            // Starting after a blank line
       [ ]{0,3}                                        // attacklab: g_tab_width - 1
       (                                               // save in $1
       <!
       (--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)   // see http://www.w3.org/TR/html-markup/syntax.html#comments and http://meta.stackoverflow.com/q/95256
       >
       [ \t]*
       (?=\n{2,})                                  // followed by a blank line
       )
       /g,hashElement);
       */
      text = text.replace(/\n\n[ ]{0,3}(<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>[ \t]*(?=\n{2,}))/g, hashElement);

      // PHP and ASP-style processor instructions (<?...?> and <%...%>)

      /*
       text = text.replace(/
       (?:
       \n\n            // Starting after a blank line
       )
       (                   // save in $1
       [ ]{0,3}        // attacklab: g_tab_width - 1
       (?:
       <([?%])     // $2
       [^\r]*?
       \2>
       )
       [ \t]*
       (?=\n{2,})      // followed by a blank line
       )
       /g,hashElement);
       */
      text = text.replace(/(?:\n\n)([ ]{0,3}(?:<([?%])[^\r]*?\2>)[ \t]*(?=\n{2,}))/g, hashElement);

      return text;
    }

    function hashElement(wholeMatch, m1) {
      var blockText = m1;

      // Undo double lines
      blockText = blockText.replace(/^\n+/, "");

      // strip trailing blank lines
      blockText = blockText.replace(/\n+$/g, "");

      // Replace the element text with a marker ("~KxK" where x is its key)
      blockText = "\n\n~K" + (g_html_blocks.push(blockText) - 1) + "K\n\n";

      return blockText;
    }

    function _RunBlockGamut(text, doNotUnhash) {
      //
      // These are all the transformations that form block-level
      // tags like paragraphs, headers, and list items.
      //
      text = _DoHeaders(text);

      // Do Horizontal Rules:
      var replacement = "<hr />\n";
      text = text.replace(/^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$/gm, replacement);
      text = text.replace(/^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$/gm, replacement);
      text = text.replace(/^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$/gm, replacement);

      text = _DoLists(text);
      text = _DoBlockQuotes(text);

      // We already ran _HashHTMLBlocks() before, in Markdown(), but that
      // was to escape raw HTML in the original Markdown source. This time,
      // we're escaping the markup we've just created, so that we don't wrap
      // <p> tags around block-level tags.
      text = _HashHTMLBlocks(text);
      text = _FormParagraphs(text, doNotUnhash);

      text = _DoCodeBlocks(text);

      return text;
    }

    function _RunSpanGamut(text) {
      //
      // These are all the transformations that occur *within* block-level
      // tags like paragraphs, headers, and list items.
      //

      text = _DoCodeSpans(text);
      text = _EscapeSpecialCharsWithinTagAttributes(text);
      text = _EncodeBackslashEscapes(text);

      // Process anchor and image tags. Images must come first,
      // because ![foo][f] looks like an anchor.
      text = _DoImages(text);
      text = _DoAnchors(text);

      // Make links out of things like `<http://example.com/>`
      // Must come after _DoAnchors(), because you can use < and >
      // delimiters in inline links like [this](<url>).
      text = _DoAutoLinks(text);

      text = text.replace(/~P/g, "://"); // put in place to prevent autolinking; reset now

      text = _EncodeAmpsAndAngles(text);
      text = _DoItalicsAndBold(text);

      // Do hard breaks:
      text = text.replace(/ *\n/g, " <br>\n");

      return text;
    }

    function _EscapeSpecialCharsWithinTagAttributes(text) {
      //
      // Within tags -- meaning between < and > -- encode [\ ` * _] so they
      // don't conflict with their use in Markdown for code, italics and strong.
      //

      // Build a regex to find HTML tags and comments.  See Friedl's
      // "Mastering Regular Expressions", 2nd Ed., pp. 200-201.

      // SE: changed the comment part of the regex

      var regex = /(<[a-z\/!$]("[^"]*"|'[^']*'|[^'">])*>|<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>)/gi;

      text = text.replace(regex, function (wholeMatch) {
        var tag = wholeMatch.replace(/(.)<\/?code>(?=.)/g, "$1`");
        tag = escapeCharacters(tag, wholeMatch.charAt(1) == "!" ? "\\`*_/" : "\\`*_"); // also escape slashes in comments to prevent autolinking there -- http://meta.stackoverflow.com/questions/95987
        return tag;
      });

      return text;
    }

    function _DoAnchors(text) {
      //
      // Turn Markdown link shortcuts into XHTML <a> tags.
      //
      //
      // First, handle reference-style links: [link text] [id]
      //

      /*
       text = text.replace(/
       (                           // wrap whole match in $1
       \[
       (
       (?:
       \[[^\]]*\]      // allow brackets nested one level
       |
       [^\[]           // or anything else
       )*
       )
       \]

       [ ]?                    // one optional space
       (?:\n[ ]*)?             // one optional newline followed by spaces

       \[
       (.*?)                   // id = $3
       \]
       )
       ()()()()                    // pad remaining backreferences
       /g, writeAnchorTag);
       */
      text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag);

      //
      // Next, inline-style links: [link text](url "optional title")
      //

      /*
       text = text.replace(/
       (                           // wrap whole match in $1
       \[
       (
       (?:
       \[[^\]]*\]      // allow brackets nested one level
       |
       [^\[\]]         // or anything else
       )*
       )
       \]
       \(                      // literal paren
       [ \t]*
       ()                      // no id, so leave $3 empty
       <?(                     // href = $4
       (?:
       \([^)]*\)       // allow one level of (correctly nested) parens (think MSDN)
       |
       [^()]
       )*?
       )>?
       [ \t]*
       (                       // $5
       (['"])              // quote char = $6
       (.*?)               // Title = $7
       \6                  // matching quote
       [ \t]*              // ignore any spaces/tabs between closing quote and )
       )?                      // title is optional
       \)
       )
       /g, writeAnchorTag);
       */

      text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\]\([ \t]*()<?((?:\([^)]*\)|[^()])*?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag);

      //
      // Last, handle reference-style shortcuts: [link text]
      // These must come last in case you've also got [link test][1]
      // or [link test](/foo)
      //

      /*
       text = text.replace(/
       (                   // wrap whole match in $1
       \[
       ([^\[\]]+)      // link text = $2; can't contain '[' or ']'
       \]
       )
       ()()()()()          // pad rest of backreferences
       /g, writeAnchorTag);
       */
      text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag);

      return text;
    }

    function writeAnchorTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
      if (m7 == undefined) m7 = "";
      var whole_match = m1;
      var link_text = m2.replace(/:\/\//g, "~P"); // to prevent auto-linking withing the link. will be converted back after the auto-linker runs
      var link_id = m3.toLowerCase();
      var url = m4;
      var title = m7;

      if (url == "") {
        if (link_id == "") {
          // lower-case and turn embedded newlines into spaces
          link_id = link_text.toLowerCase().replace(/ ?\n/g, " ");
        }
        url = "#" + link_id;

        if (g_urls.get(link_id) != undefined) {
          url = g_urls.get(link_id);
          if (g_titles.get(link_id) != undefined) {
            title = g_titles.get(link_id);
          }
        }
        else {
          if (whole_match.search(/\(\s*\)$/m) > -1) {
            // Special case for explicit empty url
            url = "";
          } else {
            return whole_match;
          }
        }
      }
      url = encodeProblemUrlChars(url);
      url = escapeCharacters(url, "*_");
      var result = "<a href=\"" + url + "\"";

      if (title != "") {
        title = attributeEncode(title);
        title = escapeCharacters(title, "*_");
        result += " title=\"" + title + "\"";
      }

      result += ">" + link_text + "</a>";

      return result;
    }

    function _DoImages(text) {
      //
      // Turn Markdown image shortcuts into <img> tags.
      //

      //
      // First, handle reference-style labeled images: ![alt text][id]
      //

      /*
       text = text.replace(/
       (                   // wrap whole match in $1
       !\[
       (.*?)           // alt text = $2
       \]

       [ ]?            // one optional space
       (?:\n[ ]*)?     // one optional newline followed by spaces

       \[
       (.*?)           // id = $3
       \]
       )
       ()()()()            // pad rest of backreferences
       /g, writeImageTag);
       */
      text = text.replace(/(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeImageTag);

      //
      // Next, handle inline images:  ![alt text](url "optional title")
      // Don't forget: encode * and _

      /*
       text = text.replace(/
       (                   // wrap whole match in $1
       !\[
       (.*?)           // alt text = $2
       \]
       \s?             // One optional whitespace character
       \(              // literal paren
       [ \t]*
       ()              // no id, so leave $3 empty
       <?(\S+?)>?      // src url = $4
       [ \t]*
       (               // $5
       (['"])      // quote char = $6
       (.*?)       // title = $7
       \6          // matching quote
       [ \t]*
       )?              // title is optional
       \)
       )
       /g, writeImageTag);
       */
      text = text.replace(/(!\[(.*?)\]\s?\([ \t]*()<?(\S+?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeImageTag);

      return text;
    }

    function attributeEncode(text) {
      // unconditionally replace angle brackets here -- what ends up in an attribute (e.g. alt or title)
      // never makes sense to have verbatim HTML in it (and the sanitizer would totally break it)
      return text.replace(/>/g, "&gt;").replace(/</g, "&lt;").replace(/"/g, "&quot;");
    }

    function writeImageTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
      var whole_match = m1;
      var alt_text = m2;
      var link_id = m3.toLowerCase();
      var url = m4;
      var title = m7;

      if (!title) title = "";

      if (url == "") {
        if (link_id == "") {
          // lower-case and turn embedded newlines into spaces
          link_id = alt_text.toLowerCase().replace(/ ?\n/g, " ");
        }
        url = "#" + link_id;

        if (g_urls.get(link_id) != undefined) {
          url = g_urls.get(link_id);
          if (g_titles.get(link_id) != undefined) {
            title = g_titles.get(link_id);
          }
        }
        else {
          return whole_match;
        }
      }

      alt_text = escapeCharacters(attributeEncode(alt_text), "*_[]()");
      url = escapeCharacters(url, "*_");
      var result = "<img src=\"" + url + "\" alt=\"" + alt_text + "\"";

      // attacklab: Markdown.pl adds empty title attributes to images.
      // Replicate this bug.

      //if (title != "") {
      title = attributeEncode(title);
      title = escapeCharacters(title, "*_");
      result += " title=\"" + title + "\"";
      //}

      result += " />";

      return result;
    }

    function _DoHeaders(text) {

      var reg = new RegExp('^[ \\t]*(#{2,3})' + '[ \\t]*' + '([^#]+?)'
          + '[ \\t]*' + '#*' + '(?:[ ]+\\{#([-_:a-zA-Z0-9]+)\\}[ ]*)?'
          + '\\n', "gm");

      text = text.replace(reg, function($0, $1, $2, $3){
        return "<h" + $1.length + ">" + _RunSpanGamut($2) + "</h" + $1.length + ">";
      });

      return text;

    }

    function _DoLists(text) {
      //
      // Form HTML ordered (numbered) and unordered (bulleted) lists.
      //

      // attacklab: add sentinel to hack around khtml/safari bug:
      // http://bugs.webkit.org/show_bug.cgi?id=11231
      text += "~0";

      // Re-usable pattern to match any entirel ul or ol list:

      /*
       var whole_list = /
       (                                   // $1 = whole list
       (                               // $2
       [ ]{0,3}                    // attacklab: g_tab_width - 1
       ([*+-]|\d+[.])              // $3 = first list item marker
       [ \t]+
       )
       [^\r]+?
       (                               // $4
       ~0                          // sentinel for workaround; should be $
       |
       \n{2,}
       (?=\S)
       (?!                         // Negative lookahead for another list item marker
       [ \t]*
       (?:[*+-]|\d+[.])[ \t]+
       )
       )
       )
       /g
       */
      var whole_list = /^(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/gm;

      if (g_list_level) {
        text = text.replace(whole_list, function (wholeMatch, m1, m2) {
          var list = m1;
          var list_type = (m2.search(/[*+-]/g) > -1) ? "ul" : "ol";

          var result = _ProcessListItems(list, list_type);

          // Trim any trailing whitespace, to put the closing `</$list_type>`
          // up on the preceding line, to get it past the current stupid
          // HTML block parser. This is a hack to work around the terrible
          // hack that is the HTML block parser.
          result = result.replace(/\s+$/, "");
          result = "<" + list_type + ">" + result + "</" + list_type + ">\n";
          return result;
        });
      } else {
        whole_list = /(\n\n|^\n?)(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/g;
        text = text.replace(whole_list, function (wholeMatch, m1, m2, m3) {
          var runup = m1;
          var list = m2;

          var list_type = (m3.search(/[*+-]/g) > -1) ? "ul" : "ol";
          var result = _ProcessListItems(list, list_type);
          result = runup + "<" + list_type + ">\n" + result + "</" + list_type + ">\n";
          return result;
        });
      }

      // attacklab: strip sentinel
      text = text.replace(/~0/, "");

      return text;
    }

    var _listItemMarkers = { ol: "\\d+[.]", ul: "[*+-]" };

    function _ProcessListItems(list_str, list_type) {
      //
      //  Process the contents of a single ordered or unordered list, splitting it
      //  into individual list items.
      //
      //  list_type is either "ul" or "ol".

      // The $g_list_level global keeps track of when we're inside a list.
      // Each time we enter a list, we increment it; when we leave a list,
      // we decrement. If it's zero, we're not in a list anymore.
      //
      // We do this because when we're not inside a list, we want to treat
      // something like this:
      //
      //    I recommend upgrading to version
      //    8. Oops, now this line is treated
      //    as a sub-list.
      //
      // As a single paragraph, despite the fact that the second line starts
      // with a digit-period-space sequence.
      //
      // Whereas when we're inside a list (or sub-list), that line will be
      // treated as the start of a sub-list. What a kludge, huh? This is
      // an aspect of Markdown's syntax that's hard to parse perfectly
      // without resorting to mind-reading. Perhaps the solution is to
      // change the syntax rules such that sub-lists must start with a
      // starting cardinal number; e.g. "1." or "a.".

      g_list_level++;

      // trim trailing blank lines:
      list_str = list_str.replace(/\n{2,}$/, "\n");

      // attacklab: add sentinel to emulate \z
      list_str += "~0";

      // In the original attacklab showdown, list_type was not given to this function, and anything
      // that matched /[*+-]|\d+[.]/ would just create the next <li>, causing this mismatch:
      //
      //  Markdown          rendered by WMD        rendered by MarkdownSharp
      //  ------------------------------------------------------------------
      //  1. first          1. first               1. first
      //  2. second         2. second              2. second
      //  - third           3. third                   * third
      //
      // We changed this to behave identical to MarkdownSharp. This is the constructed RegEx,
      // with {MARKER} being one of \d+[.] or [*+-], depending on list_type:

      /*
       list_str = list_str.replace(/
       (^[ \t]*)                       // leading whitespace = $1
       ({MARKER}) [ \t]+               // list marker = $2
       ([^\r]+?                        // list item text   = $3
       (\n+)
       )
       (?=
       (~0 | \2 ({MARKER}) [ \t]+)
       )
       /gm, function(){...});
       */

      var marker = _listItemMarkers[list_type];
      var re = new RegExp("(^[ \\t]*)(" + marker + ")[ \\t]+([^\\r]+?(\\n+))(?=(~0|\\1(" + marker + ")[ \\t]+))", "gm");
      var last_item_had_a_double_newline = false;
      list_str = list_str.replace(re,
          function (wholeMatch, m1, m2, m3) {
            var item = m3;
            var leading_space = m1;
            var ends_with_double_newline = /\n\n$/.test(item);
            var contains_double_newline = ends_with_double_newline || item.search(/\n{2,}/) > -1;

            if (contains_double_newline || last_item_had_a_double_newline) {
              item = _RunBlockGamut(_Outdent(item), /* doNotUnhash = */true);
            }
            else {
              // Recursion for sub-lists:
              item = _DoLists(_Outdent(item));
              item = item.replace(/\n$/, ""); // chomp(item)
              item = _RunSpanGamut(item);
            }
            last_item_had_a_double_newline = ends_with_double_newline;
            return "<li>" + item + "</li>\n";
          }
      );

      // attacklab: strip sentinel
      list_str = list_str.replace(/~0/g, "");

      g_list_level--;
      return list_str;
    }

    function _DoCodeBlocks(text) {
      //
      //  Process Markdown `<pre><code>` blocks.
      //

      /*
       text = text.replace(/
       (?:\n\n|^)
       (                               // $1 = the code block -- one or more lines, starting with a space/tab
       (?:
       (?:[ ]{4}|\t)           // Lines must start with a tab or a tab-width of spaces - attacklab: g_tab_width
       .*\n+
       )+
       )
       (\n*[ ]{0,3}[^ \t\n]|(?=~0))    // attacklab: g_tab_width
       /g ,function(){...});
       */

      // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
      //text += "~0"

      var reg = new RegExp('(?:(^|[\n]*)?)(\{\{\{)[\n]*([\\s\\S]+?[\\s\\S][\{\}]*)(\}\}\})', 'g');
      text = text.replace(reg,
          function (wholeMatch, m1, m2, m3, m4) {
            var codeblock = m3;
            codeblock = _EncodeCode(_Outdent(codeblock));
            codeblock = _Detab(codeblock);
            codeblock = codeblock.replace(/^\n+/g, ""); // trim leading newlines
            codeblock = codeblock.replace(/\n+$/g, ""); // trim trailing whitespace
            codeblock = codeblock.replace(/\n/g, '<br/>');

            // Modify by kk
            codeblock = codeblock.replace(/\&lt;\/p\&gt;/g, "");
            codeblock = codeblock.replace(/&lt;\p\&gt;/g, "");
            codeblock = codeblock.replace(/\&lt;br\&gt;/g, "");

            return '\n\n<pre class="prettyprint">' + codeblock + '</pre>\n\n';
          }
      );

      // attacklab: strip sentinel
      //text = text.replace(/~0/, "");

      return text;
    }

    function hashBlock(text) {
      text = text.replace(/(^\n+|\n+$)/g, "");
      return "\n\n~K" + (g_html_blocks.push(text) - 1) + "K\n\n";
    }

    function _DoCodeSpans(text) {
      //
      // * Backtick quotes are used for <code></code> spans.
      //
      // * You can use multiple backticks as the delimiters if you want to
      //   include literal backticks in the code span. So, this input:
      //
      //      Just type ``foo `bar` baz`` at the prompt.
      //
      //   Will translate to:
      //
      //      <p>Just type <code>foo `bar` baz</code> at the prompt.</p>
      //
      //   There's no arbitrary limit to the number of backticks you
      //   can use as delimters. If you need three consecutive backticks
      //   in your code, use four for delimiters, etc.
      //
      // * You can use spaces to get literal backticks at the edges:
      //
      //      ... type `` `bar` `` ...
      //
      //   Turns to:
      //
      //      ... type <code>`bar`</code> ...
      //

      /*
       text = text.replace(/
       (^|[^\\])       // Character before opening ` can't be a backslash
       (`+)            // $2 = Opening run of `
       (               // $3 = The code block
       [^\r]*?
       [^`]        // attacklab: work around lack of lookbehind
       )
       \2              // Matching closer
       (?!`)
       /gm, function(){...});
       */

      text = text.replace(/(^|[^\\])(`+)([^\r]*?[^`])\2(?!`)/gm,
          function (wholeMatch, m1, m2, m3, m4) {
            var c = m3;
            c = c.replace(/^([ \t]*)/g, ""); // leading whitespace
            c = c.replace(/[ \t]*$/g, ""); // trailing whitespace
            c = _EncodeCode(c);
            c = c.replace(/:\/\//g, "~P"); // to prevent auto-linking. Not necessary in code *blocks*, but in code spans. Will be converted back after the auto-linker runs.
            return m1 + "<code>" + c + "</code>";
          }
      );

      return text;
    }

    function _EncodeCode(text) {
      //
      // Encode/escape certain characters inside Markdown code runs.
      // The point is that in code, these characters are literals,
      // and lose their special Markdown meanings.
      //
      // Encode all ampersands; HTML entities are not
      // entities within a Markdown code span.
      text = text.replace(/&/g, "&amp;");

      // Do the angle bracket song and dance:
      text = text.replace(/</g, "&lt;");
      text = text.replace(/>/g, "&gt;");

      // Now, escape characters that are magic in Markdown:
      text = escapeCharacters(text, "\*_{}[]\\", false);

      // jj the line above breaks this:
      //---

      //* Item

      //   1. Subitem

      //            special char: *
      //---

      return text;
    }

    function _DoItalicsAndBold(text) {

      // <strong> must go first:
      text = text.replace(/([\S\W_]|^)(\*\*|__)(?=\S)([^\r]*?\S[\*_]*)\2([\W_]|$)/g,
          "$1<strong>$3</strong>$4");

      text = text.replace(/([\S\W_]|^)(\*|_)(?=\S)([^\r\*_]*?\S)\2([\W_]|$)/g,
          "$1<em>$3</em>$4");

      return text;
    }

    function _DoBlockQuotes(text) {

      /*
       text = text.replace(/
       (                           // Wrap whole match in $1
       (
       ^[ \t]*>[ \t]?      // '>' at the start of a line
       .+\n                // rest of the first line
       (.+\n)*             // subsequent consecutive lines
       \n*                 // blanks
       )+
       )
       /gm, function(){...});
       */
      text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
          function (wholeMatch, m1) {
            var bq = m1;

            // attacklab: hack around Konqueror 3.5.4 bug:
            // "----------bug".replace(/^-/g,"") == "bug"

            bq = bq.replace(/^[ \t]*>[ \t]?/gm, "~0"); // trim one level of quoting

            // attacklab: clean up hack
            bq = bq.replace(/~0/g, "");

            bq = bq.replace(/^[ \t]+$/gm, "");     // trim whitespace-only lines
            bq = _RunBlockGamut(bq);             // recurse

            bq = bq.replace(/(^|\n)/g, "$1  ");
            // These leading spaces screw with <pre> content, so we need to fix that:
            bq = bq.replace(
                /(\s*<pre>[^\r]+?<\/pre>)/gm,
                function (wholeMatch, m1) {
                  var pre = m1;
                  // attacklab: hack around Konqueror 3.5.4 bug:
                  pre = pre.replace(/^  /mg, "~0");
                  pre = pre.replace(/~0/g, "");
                  return pre;
                });

            return hashBlock("<blockquote>\n" + bq + "\n</blockquote>");
          }
      );
      return text;
    }

    function _FormParagraphs(text, doNotUnhash) {
      //
      //  Params:
      //    $text - string to process with html <p> tags
      //

      // Strip leading and trailing lines:
      text = text.replace(/^\n+/g, "");
      text = text.replace(/\n+$/g, "");

      var grafs = text.split(/\n{2,}/g);
      var grafsOut = [];

      var markerRe = /~K(\d+)K/;

      //
      // Wrap <p> tags.
      //
      var end = grafs.length;
      for (var i = 0; i < end; i++) {
        var str = grafs[i];

        // if this is an HTML marker, copy it
        if (markerRe.test(str)) {
          grafsOut.push(str);
        }
        else if (/\S/.test(str)) {
          str = _RunSpanGamut(str);
          str = str.replace(/^([ \t]*)/g, "<p>");
          str += "</p>"
          grafsOut.push(str);
        }

      }
      //
      // Unhashify HTML blocks
      //
      if (!doNotUnhash) {
        end = grafsOut.length;
        for (var i = 0; i < end; i++) {
          var foundAny = true;
          while (foundAny) { // we may need several runs, since the data may be nested
            foundAny = false;
            grafsOut[i] = grafsOut[i].replace(/~K(\d+)K/g, function (wholeMatch, id) {
              foundAny = true;
              return g_html_blocks[id];
            });
          }
        }
      }
      return grafsOut.join("\n\n");
    }

    function _EncodeAmpsAndAngles(text) {
      // Smart processing for ampersands and angle brackets that need to be encoded.

      // Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
      //   http://bumppo.net/projects/amputator/
      text = text.replace(/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/g, "&amp;");

      // Encode naked <'s
      text = text.replace(/<(?![a-z\/?\$!])/gi, "&lt;");

      return text;
    }

    function _EncodeBackslashEscapes(text) {
      //
      //   Parameter:  String.
      //   Returns:    The string, with after processing the following backslash
      //               escape sequences.
      //

      // attacklab: The polite way to do this is with the new
      // escapeCharacters() function:
      //
      //     text = escapeCharacters(text,"\\",true);
      //     text = escapeCharacters(text,"`*_{}[]()>#+-.!",true);
      //
      // ...but we're sidestepping its use of the (slow) RegExp constructor
      // as an optimization for Firefox.  This function gets called a LOT.

      text = text.replace(/\\(\\)/g, escapeCharacters_callback);
      text = text.replace(/\\([`*_{}\[\]()>#+-.!])/g, escapeCharacters_callback);
      return text;
    }

    function _DoAutoLinks(text) {

      // note that at this point, all other URL in the text are already hyperlinked as <a href=""></a>
      // *except* for the <http://www.foo.com> case

      // automatically add < and > around unadorned raw hyperlinks
      // must be preceded by space/BOF and followed by non-word/EOF character
      text = text.replace(/(^|\s)(https?|ftp)(:\/\/[-A-Z0-9+&@#\/%?=~_|\[\]\(\)!:,\.;]*[-A-Z0-9+&@#\/%=~_|\[\]])($|\W)/gi, "$1<$2$3>$4");

      //  autolink anything like <http://example.com>

      var replacer = function (wholematch, m1) { return "<a href=\"" + m1 + "\">" + pluginHooks.plainLinkText(m1) + "</a>"; }
      text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);

      // Email addresses: <address@domain.foo>
      /*
       text = text.replace(/
       <
       (?:mailto:)?
       (
       [-.\w]+
       \@
       [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
       )
       >
       /gi, _DoAutoLinks_callback());
       */

      var email_replacer = function(wholematch, m1) {
        var mailto = 'mailto:'
        var link
        var email
        if (m1.substring(0, mailto.length) != mailto){
          link = mailto + m1;
          email = m1;
        } else {
          link = m1;
          email = m1.substring(mailto.length, m1.length);
        }
        return "<a href=\"" + link + "\">" + pluginHooks.plainLinkText(email) + "</a>";
      }
      text = text.replace(/<((?:mailto:)?([-.\w]+\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+))>/gi, email_replacer);

      return text;
    }

    function _UnescapeSpecialChars(text) {
      //
      // Swap back in all the special characters we've hidden.
      //
      text = text.replace(/~E(\d+)E/g,
          function (wholeMatch, m1) {
            var charCodeToReplace = parseInt(m1);
            return String.fromCharCode(charCodeToReplace);
          }
      );
      return text;
    }

    function _Outdent(text) {
      //
      // Remove one level of line-leading tabs or spaces
      //

      // attacklab: hack around Konqueror 3.5.4 bug:
      // "----------bug".replace(/^-/g,"") == "bug"

      text = text.replace(/^(\t|[ ]{1,4})/gm, "~0"); // attacklab: g_tab_width

      // attacklab: clean up hack
      text = text.replace(/~0/g, "")

      return text;
    }

    function _Detab(text) {
      if (!/\t/.test(text))
        return text;

      var spaces = ["    ", "   ", "  ", " "],
          skew = 0,
          v;

      return text.replace(/[\n\t]/g, function (match, offset) {
        if (match === "\n") {
          skew = offset + 1;
          return match;
        }
        v = (offset - skew) % 4;
        skew = offset + 1;
        return spaces[v];
      });
    }

    //
    //  attacklab: Utility functions
    //

    var _problemUrlChars = /(?:["'*()[\]:]|~D)/g;

    // hex-encodes some unusual "problem" chars in URLs to avoid URL detection problems
    function encodeProblemUrlChars(url) {
      if (!url)
        return "";

      var len = url.length;

      return url.replace(_problemUrlChars, function (match, offset) {
        if (match == "~D") // escape for dollar
          return "%24";
        if (match == ":") {
          if (offset == len - 1 || /[0-9\/]/.test(url.charAt(offset + 1)))
            return ":";
          if (url.substring(0, 'mailto:'.length) === 'mailto:')
            return ":";
          if (url.substring(0, 'magnet:'.length) === 'magnet:')
            return ":";
        }
        return "%" + match.charCodeAt(0).toString(16);
      });
    }


    function escapeCharacters(text, charsToEscape, afterBackslash) {
      // First we have to escape the escape characters so that
      // we can build a character class out of them
      var regexString = "([" + charsToEscape.replace(/([\[\]\\])/g, "\\$1") + "])";

      if (afterBackslash) {
        regexString = "\\\\" + regexString;
      }

      var regex = new RegExp(regexString, "g");
      text = text.replace(regex, escapeCharacters_callback);

      return text;
    }


    function escapeCharacters_callback(wholeMatch, m1) {
      var charCodeToEscape = m1.charCodeAt(0);
      return "~E" + charCodeToEscape + "E";
    }

  }; // end of the Markdown.Converter constructor
})();
